Charging of an internal battery of a mobile phone is performed in a state in which the mobile phone is placed on a stand. A so-called hand-free set including such a stand provided with a microphone, a speaker, and so on for enabling communication in a state in which the mobile phone is placed on the stand is disclosed in JP-A-10-98512 and JP-A-10-285254.
In recent years, a music delivery service via a mobile phone is in the course of coming into practical use. In the aforementioned hand-free set, since arrangement of stereo reproduction is not taken into account, only monaural reproduction is available even when taking advantage of such music delivery service. Also, although it is necessary to arrange a plurality of speakers at a suitable distance in order to realize reproduction in association with stereo feeling, since such a stand is downsized in association with downsizing of the mobile phone, such an arrangement of the speakers is impossible to realize.
As an improved stereo reproduction, there exists reproduction which provides audiences with “surround” feeing, so-called derived surround reproduction. However, reproduction of such type is also impossible in the aforementioned hand-free set. The term “derived surround reproduction” represents generation of sound which provides the audience with a feeling as if there were sound sources not only in front, but also on the sides or in the back from a plurality of speakers arranged only in front.
In view of the aforementioned problems, it is an object of the present invention to provide a speaker system capable of derived surround reproduction or stereo reproduction, which also functions as a stand capable of power supply to a mobile phone and of hand-free communication.